That's ~6% of the 9M. Not nothing but not a glaring amount. I'm seeing that there are 1.7M total SWEs in the US, which would bring the H1B % to 30%, assuming all are SWEs. This would make it a significant amount, not sure if it's enough to suppress wages / pass on US persons if they attempted it.
One look at the top H1B employers should stop this narrative however, because those companies do not pay near peanuts.
So it's fairer to it's really ~490K vs 8M.